This invention pertains to a network management system that manages or controls data flow in an asymmetric network in which multiple users share a common broadband medium that conveys high speed data. More particularly, this invention is directed to a network management system for managing bandwidth and controlling configuration parameters, including those affecting channel assignment, bandwidth allocation, transmit power setting, address assignment and the like in an asymmetric network communication system.
Medium access control provided by the present invention differs from contention-based and token-ring schemes in that a centralized network manager or controller regulates utilization of bandwidth by multiple remote devices comunicating over a shared medium rather than permitting the remote devices themselves to take control over the medium without prior authorization. Further, the present invention differs from asymmetric networks that are provided by dedicated ADSL networks in that multiple remote devices share a medium.
The invention has application to CATV broadband networks, wireless networks including cellular and satellite broadcast systems, television broadcast systems, hybrid/fiber coaxial networks, cable communication systems, and telephony systems in which at least a portion of the communication paths between communicating nodes is asymmetric. Nodes of the network include servers, host computers, network devices and appliances, RF and cable modems and computing devices. In particular, the invention is directed to methods, architectural structures, systems and components thereof useful for providing, facilitating and managing asymmetric communication using various switching or routing protocols, including ATM switching and IP routing, at various layers including the physical, link and network layers.
A primary objective of the present invention is to provide an architectural structure, control system and method for allocating bandwidth in an asymmetric network system.
Another objective of the present invention is to provide a method and system useful in an asymmetric network for managing configuration of remote devices.
A further objective of the present invention is to provide methods and systems for obtaining maximum bandwidth utilization by apportioning available bandwidth among multiple remote devices in an asymmetric network utilizing a shared medium.
A further objective of the present invention is to provide an architecture which permits independent scalability of upstream and downstream capacity in an asymmetric network system.
A further objective of the present invention is to provide a packet based control scheme for managing with a configuration of remote devices in an asymmetric network vacation system.
It is yet another objective of the present invention to provide thorough packet based control flexibility in assigning configuration parameters and bandwidth utilization through provision of a downloadable network operating software from a network management center to multiple remote devices.
It is yet a further objective of the present invention to provide methods and systems for collecting usage data and statistical operating parameters of the network which are subsequently used for bandwidth management and configuration control of remote devices.
It is yet a further object of of the present invention to provide methods and systems for altering transmit level, frequency or time slot channel assignments, global and local address assignments, account ID assignments and other properties of remote devices connected to a shared medium in asymmetric network.
It is yet a further object of the present invention to provide a management system which provides account administration for remote devices connected thereto.
In accordance with one aspect of the invention, an asymmetric network management system, remote device or method involves the use of at least one downstream channel carried in a broadband transmission medium and at least one upstream channel operating in the same or different medium at a different speed or under a different protocol. The invention enables a host computer to transfer information with a plurality of remote devices over a shared broadband medium. A modular architecture of the network management system permits independent scalability of upstream and downstream capacity separately for each of the upstream and downstream physical paths, and a network manager in the system manages configuration parameters of the downstream bandwidth allocated to remote devices. The network manger may effect allocation of downstream bandwidth to requesting devices according to bandwidth utilization by other devices, bandwidth demand by the requesting remote device, class or grade of service of the requesting remote device or bandwidth guaranteed to other remote devices. Configuration parameters remotely managed by the network manager include device addresses (global and local), transmission credit values, upstream channel assignments, upstream transmit power levels.
An additional aspect of the invention includes management of configuration and bandwidth through control and response packets generated at the network operations center and the remote devices, respectively. Control packets include poll packets that request, among other things, upstream lo transmission requests. Configuration packets instruct remote devices to assume an operational state, return status or statistical data. Response packets transmitted by the remote devices provide information to the network operation center for control purposes or to confirm their state of operation. Information packets are also sent in both directions. IP or ATM encapsulation, as well as forward error correction and encryption, are employed. The invention has application in broadband networks including RF, satellite and cable media, including those with telephony or router return paths.
These and other aspects, advantages and benefits of the invention will become more readily apparent in light of the succeeding disclosure and accompanying drawings. The invention, though, is pointed out with particularity by the appended claims.
FIG. 1 depicts a layout of a preferred architectural structure of the invention including an independently operating network manager, upstream controller and downstream controller.
FIG. 2 is a functional block diagram of operational components of the upstream and downstream controllers in a cable-return asymmetric network system.
FIG. 3 is a functional block diagram of operational components of upstream and downstream controllers for a telephony-return asymmetric network system.
FIG. 4A illustrates the transmitter and receiver components of multiple remote devices in communication with respective transmitters and receivers of a two-way cable system.
FIG. 4B is a depiction of the state machine illustrating generation of upstream data and DONE packets transmitted by the remote devices.
FIG. 4C depicts a state diagram of remote devices in a transmit power level setting scheme.
FIG. 4D shows a packet structure of a downstream data link frame encoding scheme.
FIG. 4E depicts a Reed-Solomon encoded packet structure.
FIG. 4F illustrates interleaving applied in a forward error correction scheme on the downstream channel.
FIG. 4G illustrates the packet structure of upstream frame transmitted by remote devices.
FIGS. 4H and 4I depict constraints of Viterbi encoding used in upstream transmission from remote devices.
FIG. 5 illustrates the sequence of remote device initialization and configuration.